Bauxite is the primary ore of aluminum. Almost all of the aluminum ever produced has been recovered from bauxite. There are several small bauxite deposits in the United States, but at least 99% of the bauxite used in the United States is imported. The United States is also a major importer of metallic aluminum. Bauxite is a sedimentary rock with a relatively high aluminum content. It is the main source of aluminum in the world. Bauxite consists mainly of the aluminum minerals gibbsite (Al (OH) 3), boehmite (γ-AlO (OH)) and diaspora (α-AlO (OH)), mixed with two iron oxides, goethite (FeO (OH)) and hematite (Fe 2 O 3), clay mineral kaolinite (Al 2 Si 2 O 5 (OH)) and a small amount of anatase (TiO 2) and ilmenite (FeTiO 3 or FeO.TiO 2).